A method and a device for checking the centering of spectacle lenses mounted into a spectacle frame are described in U.S. Pat. No. 9,022,565 B2. The method involves firstly determining the positions of permanent markings in the spectacle lenses relative to the frame. The setpoint centering points on the spectacle lenses are determined from the positions determined. Actual centering points for the wearer of the spectacles are determined with the aid of a video centering device. Actual and setpoint centering points are then compared with one another. Accordingly, this method involves checking (possibly automatically) the position of the spectacle lenses seated by grinding on the basis of the permanent engravings. This method functions only in the case of spectacle lenses on which such permanent engravings are also present.
DE 10 2015 211 879 A1, from which the disclosure proceeds, describes a device and a method for measuring the refractive power distribution of a spectacle lens of spectacles arranged in a measurement position. In the method, the spectacles are arranged in a measurement position. A test structure is then provided. The imaging of the test structure is then captured by way of an imaging beam path which passes through one of the spectacle lenses of the spectacles arranged in the measurement position. The refractive power distribution of the spectacle lens is then determined from the coordinates of the test structure and the captured imaging of the test structure and from the spatial position of the spectacle lens relative to the test structure or the imaging of the test structure. This method is also suitable for measuring spectacle lenses without permanent engravings.
Although both the above-described methods and arrangements have basically proved worthwhile, there is a need for a simple means for process control.